The family Aetalionidae is primarily Neotropical, but the subfamily Aetalioninae includes the New World genus Aetalion recorded from the Nearctic (Arizona and Florida) and Neotropical regions, and the Old World genus Darthula of the Indomalayan region. All members of the second aetalionid subfamily, Biturritiinae, occur only in the Neotropical region.

Frontoclypeus flat or weakly convex, not produced anteroventrally. Distance from eye to base of forewing greater than half eye width. Pronotum not produced posteriorly over the scutellum; pronotal projection, if present, produced dorsomedially (Biturritia). Scutellum fully visible, usually strongly convex basally and keeled apically (keel strong in many Biturritiinae), rarely depressed, often elongate. Forewings with veins R and M fused basally (share common stem). Prothoracic trochanter and femur immovably fused (suture may be visible). Male and female pygofer with pair of processes produced posteroventrally (processes weak in Mina, at least in females, and in Tropidaspsis). Nymph with abdominal tergum IX not forming sheath around segment X (ventromedial lobes, when present, free), anal opening dorsal or posterior.